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<head>
    <meta charset="UTF-8">
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    <title>Document</title>
</head>

<body>
    <button id="btn">cors跨域申请</button>
    <script>
        btn.onclick = function () {
            const xhr = new XMLHttpRequest();
            xhr.open('post', 'http://127.0.0.1:5000/test')
            xhr.setRequestHeader(
                'content-type',
                'application/x-www-form-urlencoded'
            );
            xhr.send();
        }
    </script>
</body>

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